<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="lib/react.development.js"></script>
    <script src="lib/react-dom.development.js"></script>
    <script src="lib/babel.min.js"></script>
</head>
<body>
<div id="root">

</div>
</body>
<script type="text/babel">
    const root = ReactDOM.createRoot(document.querySelector("#root"));
    let num = 1;
    function rend(){
        root.render((
            <div>
                {num}
                <button onClick={()=>{
                    num++;
                    rend();
                }}>点我</button>
            </div>
        ))
    }
    rend();
</script>
</html>